1. Department of Theoretical Physics, University of Łódź, ul. Pomorska 149/53, 90-236, Łódź, Poland
2. Institute for Theoretical Physics, University of Wrocław, pl. M. Borna 9, 50-205 Wrocław, Poland
3. Insitute of Physics, Jagiellonian University, ul. Reymonta 4, Kraków, Poland